Measuring correct backlink number in Yahoo (YBL) is not as simple as it looks like at first glance. Many sites providing YBL numbers are showing different numbers. What is the right method? I never use Baclink tools or dedicated web-pages. I rely only on rearch engines readings. Let's take my Dell webshop website http://shop.it.ee/ and check it's backlinks.
Yahoo re-directs You to Site Explorer page, not to traditional search result page.
Now You see 2 important numbers.
Pages means Yahoo indexed pages -- YIP. In Google You may query site:shop.it.ee, so You can do in Yahoo, but directed to the very same Yahoo page.
Inlinks show incoming (back-) links -- YBL. From SEO perspective, it's important to take account true incoming links, so exclude Your own domain links "Except from this domain", from other pages of same website. As You normally optimize whole site, not only main page etc, choose "Entire Site", to get all external incoming links to Your site. Normally, title page is main linking subject, still considerable amount of links are landing to sub-pages.
So, the right answer is YBL = 714, by my personal interpretation.